Accumulators



June 1956 T. J. MCCUISTION 2,748,801

ACCUMULATORS Filed Oct. 22, 1955 INVENTOR. 7b/ my J. Ma 60/5770 BY I Wm United States Patent ACCUMULATORS Tommy J. McCuistion, Euclid, Ohio Application October 22, 1953, Serial No. 387,651 6 Claims. (Cl. 138-31) This invention relates to the art of accumulators of the piston type.

As explainedin my several co-pending patent applications, the piercing of the wall of the liquid-storage chamber of a piston type of accumulator in an airplane, for instance, might cause sufiicient increase in internal pressure for an explosion-like bursting of the accumulator walls and a consequent=scattering of the metal particles. This, of course, might prove very dangerous and hence this type 'of accumulator is a real hazard under such conditions. It is objectionable also because of the transmission of vibrations or surges due to the operation of the pump connected to the same.

Accordingly, with these conditions in mind, one object of my present invention is to devise a piston type of accumulator with means for absorbing practically instantaneously any increased internal pressure due to the displacement of a bullet or other objectpiercing'the wall and entering the liquid-storage chamber of the accumulator.

Another object is to devise an accumulator of this type that is capable of absorbing minor fluctuations or surges of internal pressure that may be due to impulses of the pump or other hydraulic mechanism associated therewith.

Another object is to devise an accumulator of this type in which the piston itself is formed with a'chamber having located therewithin a flexible 'body and which has means of communication through the walls of'the piston chamber so that the flexible body may respond to the force of the pressure within the liquid-storage chamber.

Another object is to devise such an accumulator in which the pressure-responsive means within the piston consists of a gas-filled closed self-contained bellows of flexible material.

Other objects will appear from the following description and claims when considered together with the accompanying drawing.

Fig. 1 is a longitudinal sectional view of one form of accumulator embodying my present invention;

Fig. 2 is a longitudinal sectional'view of a'modification thereof;

Fig. 3 is a sectional view taken on line 3-3 of Fig. 2; and

Fig. 4 is a longitudinal sectional view of a still further modification embodying my present invention.

It is to be understood that the present "forms of device as herein disclosed are merely "for the purpose of illustration and that there .might be still further modifications thereof without departing from the spirit of my invention as herein set forth and'claimed.

Referring now to the form of device illustrated in Fig. 1 of the accompanying drawing, the metal cylinder 1 has its two ends turned inwardly and has its two end heads or closures 2 and 3, each of which has an O ring for sealing. The interior of the cylinder is divided by the piston 4 into a liquid-containing chamber 5 and a Fatented June 5, 1956 ice '2 chamber 6 for a gaseous body. The end head 2 has a nozzle 2a for connection to a source of supply and there may be provided a suitable form of screw-threaded closure 2b therefor. The end-head 3 likewise has a nozzle 3a which may be fitted with a conventional air valve unit 3b for connection to the source of supply.

The piston may be provided with multiple 0 rings 7 for sealing, three being here shown, and with a vent 8 for each space between the same so as to prevent pressure lock. The piston in each of the other present formsof device may be so provided although only two such rings are indicated in Figs. 2 and 4.

In each of the several forms of device herein disclosed, the body of the piston may be identified as being of substantially I form in cross section. Upon the side of the'piston towards the liquid-containing chamber 5 in Fig. 1 of the drawing, the space within the annular flange of the piston is enclosed by means of a disk 9 that is seated upon an annular shoulder 9a and is held in suchposition by peening over the edge portion into an annular flange 9b. In this way there is enclosed within the piston itself an auxiliary chamber of sub staritial capacity within which is placed the gas-filled bladder'or balloon 10 with a conventional needle-type of valve 10a by which'the same may be filled with the gas and then closed. In this case the valve extends inwardly of the flexible bladder or balloon so as to be contained within'the auxiliary chamber but access may be had thereto through the central one of the multiple openings 11 provided in the disk 9. By means of these openings 11 the force of any excess pressure within the liquid-storage chamber 5 may be transmitted to and exerted upon the flexible bladder or balloon 10. Any such excessive internal pressure that may be caused by thepiercing of the liquid-containing chamber, as above explained, may first be exerted upon and absorbed at least to some extent by the gas-filled'bladder 10; and then, if need be, any pressure may cause movement of the piston bodily along the cylinder so as to cause compression of .the gas within the chamber 6 and thereby compensate still .further for the excessive pressure within the liquid-storage chamber as maybe required so as to prevent bursting of the cylinder. In each of the present forms of device, the bladder or balloon may be made of any suitable flexible material.

In the form of device illustrated in Fig. 2, the structure is substantially the same as in Fig. 1 hereof except that the flexible gas-filled bladder or balloon 10 is provided with an air valve 12 which extends through and is fixedly mounted in the center of the perforated disk 13 which, in turn, has screw-threaded engagement in thepiston body. The valve 12 will permit the bladder or balloon 10 to be filled with the gas to the extent desired and the pressure of such gas therewithin will then close and maintain closed this valve 12. Any suitable number of apertures 14 may be provided in the disk 13 so as to permit the force of any excessive pressure within the liquid-containing chamber to be transmitted therethrough to-the gas-filled bladder and to be absorbed thereby atleast to apartial extent. In order to accom modate the valve assembly 12, which protrudes through the disk .13, the end head 15 hasits central inner surface suitably recessed, as indicated byreference numeral 15a. The end-head 15 alsohas .anozzle 15b for connection to thesource of liquid supply and a suitable screw plug for closing the same. In this form of device the end head 15 may'have screw-threaded engagement with the end of the cylinder.

Likewisein the form of device illustrated in Fig. 4 of the present drawing, the cylinder 1" may have the end heads connected thereto by means of screw-threaded engagement or as in Fig. 1 or in any other suitable manner. The end head for the liquid-containing chamber may have the same form of nozzle for connection to the source of liquid supply as illustrated in either Fig. 1 or Fig. 2 of the present drawing, while the other end head 16 may have the form of valve here illustrated instead of that shown in Figs. 1 and 2. Such variation in the form of end head and the securing means therefor may be a matter of choice. In Fig. 4 the apertured disk 17 has seating engagement upon an annular inwardly extending flange 16a peened over inwardly about the opening in the end head and serves as an abutment for the coil spring 18 which engages at its other end against the imperforate disk 19 so as to cause the same to have closing engagement against the inner end of the open screw-threaded plug 20 in the nozzle 16b of the end head 16. Inward pressure upon the disk 19 will force the same to open position against the tension of the spring 18 so as to permit gas to be supplied to the cham ber 6" as it may then flow around the disk 19 and through the perforated disk 17. Upon release of the inward pressure upon the disk 19, it will be automatically closed and held closed by the spring 18 so as to maintain the gas pressure within its chamber. The inward pressure of the gas supply itself may serve to open and hold open the disk 19 while supplying gas to the chamber 6". Likewise the disk 19 may be opened by inserting a suitable tool through the nozzle 20 so as to permit relief of the gas pressure within its chamber at any time desired.

In Fig. 4 the apertured disk 9" is secured in position in the same manner as the disk 9 in Fig. 1 so as to enclose the flexible gas-filled bladder or balloon 10" that may be made of light metal or any other suitable flexible material, as above noted. Balloon 10" may have a oneway valve 12" extending through the plunger into the chamber 6" and adapted to permit the entrance of air or gas thereinto but not therefrom; and the valve 12" will be confined within the cupped-out space provided in the corresponding side of the plunger. The valve 12" in Fig. 4 is shown with a cap but this may be omitted if so desired.

The relative air or gas pressures within the main and auxiliary chambers may be whatever is desired; and in each of the present forms of device the gas-filled flexible bladder or balloon may substantially fill the auxiliary chamber within the piston and will respond in a sensitive manner to any excessive pressure in the liquidcontaining chamber as well as vibrations. There may also be absorption by movement of the piston body itself so as to cause compression of the gas within the chamber at the opposite side of the piston.

The particular form of piston body, which may be identified as being of substantially I-form in cross section, affords extended surface area of engagement with the wall of the cylinder so as to preclude any danger of the piston cocking or binding; and the multiple 0 rings ensure dependable sealing for such extended surface engagement. Also, the cupped out space afforded upon the one side of the piston by the I cross sectional form, provides the auxiliary chamber Within which is located the flexible gas-filled bladder or balloon; while the opposite cupped-out side of the piston serves to increase the capacity of the gas chamber. The auxiliary shock-absorbing bladder or balloon may be regarded as being separate from the main gas-filled chamber and more directly responsive and more sensitive to any excessive pressure within the liquid-containing chamber.

In each of the several forms of my present invention there is involved a comparatively simple structure which, however, affords substantially increased capacity for absorption of any excessive pressure or vibrations in a sensitive, quick, efiicient and dependable manner.

What I claim is:

1. An accumulator comprising a cylinder, a piston reciprocatable longitudinally within said cylinder and dividing the interior thereof into separate chambers for a liquid and a gaseous body, respectively, said chambers having inlet and outlet openings through the wall of said cylinder for the liquid and gaseous body, respectively, said piston having transversely disposed walls spaced from each other so as to provide a space therebetween of substantial extent lengthwise of the cylinder, and a flexible completely closed gas-filled envelope enclosed within said space in the piston, and the said wall of the piston adjacent the liquid-containing chamber being provided with means for transmission of the liquid pressure therethrough to said envelope.

2. An accumulator comprising a cylinder, a piston reciprocatable longitudinally within said cylinder and dividing the interior thereof into separate chambers for a liquid and a gaseous body, respectively, said chambers having inlet and outlet openings through the wall of said cylinder for a liquid and gaseous body, respectively, said piston having transversely disposed walls spaced from each other so as to provide a space therebetween of substantial extent lengthwise of the cylinder, and a flexible completely closed gas-filled envelope enclosed within said space in said piston, and the said wall of the piston adjacent the liquid-containing chamber being perforated for transmission of the liquid pressure therethrough to said envelope.

3. The same structure as recited in claim 2 hereof and in which said envelope has a valve for filling and sealing the same, said valve being enclosed entirely Within said space within said piston.

4. The same structure as recited in claim 1 hereof and in which said inlet and outlet openings are in the end walls of the cylinder and in which said envelope has a valve for filling and sealing the same, said valve extending through the wall of said piston that is adjacent said liquid-containing chamber, and said. opening in the cylinder end wall of the liquid-containing chamber being so formed at its inner end as to accommodate said valve when said piston occupies position at the outer end of said liquid-containing chamber.

5. An accumulator comprising a cylinder, a piston reciprocatable longitudinally within said cylinder and dividing the interior thereof into separate chambers for a liquid and a gaseous body, respectively, said chambers having openings through said cylinder wall for the liquid and gaseous body, respectively, said piston having cupper-out portions upon its opposite sides longitudinally thereof so as to provide a substantially I-form in cross section, the cupped-out portion upon the liquidcontaining side thereof having a pressure-transmitting wall closing the same so as to provide an auxiliary chamher, a flexible gas-filled envelope within said auxiliary chamber so as to be responsive to excessive pressure within said liquid-containing chamber.

6. The same structure as recited in claim 5 hereof and in which said envelope has a one-way valve for filling said envelope, said one-way valve extending through the wall of said auxiliary chamber that is adjacent said chamber for the gaseous body.

References Cited in the file of this patent UNITED STATES PATENTS 2,417,256 Kremiller Mar. 11, 1947 2,583,215 Helm Jan. 22, 1952 2,592,613 Snyder Apr. 15, 1952 2,663,320 Snyder Dec. 22, 1953 

